* [PATCH] Centralize i386 Constants
@ 2004-08-16 1:30 Rusty Russell
2004-08-16 17:25 ` Roland Dreier
0 siblings, 1 reply; 2+ messages in thread
From: Rusty Russell @ 2004-08-16 1:30 UTC (permalink / raw)
To: Andrew Morton; +Cc: lkml - Kernel Mailing List
Name: Centralize i386 Constants
Status: Tested on 2.6.5-rc2-bk1
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (created)
__FIXADDR_TOP and PAGE_OFFSET are hardcoded in various places. I had
to change it to run the kernel under qemu-fast, so I wanted to
centralize them.
To do this, we rename vsyscall.lds to vsyscall.lds.s, and generate it
from vsyscall.lds.S.
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .9001-linux-2.6.5-rc2-bk1/arch/i386/kernel/Makefile .9001-linux-2.6.5-rc2-bk1.updated/arch/i386/kernel/Makefile
--- .9001-linux-2.6.5-rc2-bk1/arch/i386/kernel/Makefile 2004-03-20 21:20:49.000000000 +1100
+++ .9001-linux-2.6.5-rc2-bk1.updated/arch/i386/kernel/Makefile 2004-03-22 09:53:31.000000000 +1100
@@ -47,12 +47,14 @@ quiet_cmd_syscall = SYSCALL $@
cmd_syscall = $(CC) -nostdlib $(SYSCFLAGS_$(@F)) \
-Wl,-T,$(filter-out FORCE,$^) -o $@
+export AFLAGS_vsyscall.lds.o += -P -C -U$(ARCH)
+
vsyscall-flags = -shared -s -Wl,-soname=linux-gate.so.1
SYSCFLAGS_vsyscall-sysenter.so = $(vsyscall-flags)
SYSCFLAGS_vsyscall-int80.so = $(vsyscall-flags)
$(obj)/vsyscall-int80.so $(obj)/vsyscall-sysenter.so: \
-$(obj)/vsyscall-%.so: $(src)/vsyscall.lds $(obj)/vsyscall-%.o FORCE
+$(obj)/vsyscall-%.so: $(src)/vsyscall.lds.s $(obj)/vsyscall-%.o FORCE
$(call if_changed,syscall)
# We also create a special relocatable object that should mirror the symbol
@@ -63,5 +65,5 @@ $(obj)/built-in.o: $(obj)/vsyscall-syms.
$(obj)/built-in.o: ld_flags += -R $(obj)/vsyscall-syms.o
SYSCFLAGS_vsyscall-syms.o = -r
-$(obj)/vsyscall-syms.o: $(src)/vsyscall.lds $(obj)/vsyscall-sysenter.o FORCE
+$(obj)/vsyscall-syms.o: $(src)/vsyscall.lds.s $(obj)/vsyscall-sysenter.o FORCE
$(call if_changed,syscall)
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .9001-linux-2.6.5-rc2-bk1/arch/i386/kernel/vmlinux.lds.S .9001-linux-2.6.5-rc2-bk1.updated/arch/i386/kernel/vmlinux.lds.S
--- .9001-linux-2.6.5-rc2-bk1/arch/i386/kernel/vmlinux.lds.S 2004-03-20 21:20:49.000000000 +1100
+++ .9001-linux-2.6.5-rc2-bk1.updated/arch/i386/kernel/vmlinux.lds.S 2004-03-22 09:53:56.000000000 +1100
@@ -4,6 +4,7 @@
#include <asm-generic/vmlinux.lds.h>
#include <asm/thread_info.h>
+#include <asm/page.h>
OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
OUTPUT_ARCH(i386)
@@ -11,7 +12,7 @@ ENTRY(startup_32)
jiffies = jiffies_64;
SECTIONS
{
- . = 0xC0000000 + 0x100000;
+ . = __PAGE_OFFSET + 0x100000;
/* read-only */
_text = .; /* Text and read-only data */
.text : {
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .9001-linux-2.6.5-rc2-bk1/arch/i386/kernel/vsyscall.lds .9001-linux-2.6.5-rc2-bk1.updated/arch/i386/kernel/vsyscall.lds
--- .9001-linux-2.6.5-rc2-bk1/arch/i386/kernel/vsyscall.lds 2003-09-22 10:07:26.000000000 +1000
+++ .9001-linux-2.6.5-rc2-bk1.updated/arch/i386/kernel/vsyscall.lds 1970-01-01 10:00:00.000000000 +1000
@@ -1,67 +0,0 @@
-/*
- * Linker script for vsyscall DSO. The vsyscall page is an ELF shared
- * object prelinked to its virtual address, and with only one read-only
- * segment (that fits in one page). This script controls its layout.
- */
-
-/* This must match <asm/fixmap.h>. */
-VSYSCALL_BASE = 0xffffe000;
-
-SECTIONS
-{
- . = VSYSCALL_BASE + SIZEOF_HEADERS;
-
- .hash : { *(.hash) } :text
- .dynsym : { *(.dynsym) }
- .dynstr : { *(.dynstr) }
- .gnu.version : { *(.gnu.version) }
- .gnu.version_d : { *(.gnu.version_d) }
- .gnu.version_r : { *(.gnu.version_r) }
-
- /* This linker script is used both with -r and with -shared.
- For the layouts to match, we need to skip more than enough
- space for the dynamic symbol table et al. If this amount
- is insufficient, ld -shared will barf. Just increase it here. */
- . = VSYSCALL_BASE + 0x400;
-
- .text : { *(.text) } :text =0x90909090
-
- .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
- .eh_frame : { KEEP (*(.eh_frame)) } :text
- .dynamic : { *(.dynamic) } :text :dynamic
- .useless : {
- *(.got.plt) *(.got)
- *(.data .data.* .gnu.linkonce.d.*)
- *(.dynbss)
- *(.bss .bss.* .gnu.linkonce.b.*)
- } :text
-}
-
-/*
- * We must supply the ELF program headers explicitly to get just one
- * PT_LOAD segment, and set the flags explicitly to make segments read-only.
- */
-PHDRS
-{
- text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
- dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
- eh_frame_hdr 0x6474e550; /* PT_GNU_EH_FRAME, but ld doesn't match the name */
-}
-
-/*
- * This controls what symbols we export from the DSO.
- */
-VERSION
-{
- LINUX_2.5 {
- global:
- __kernel_vsyscall;
- __kernel_sigreturn;
- __kernel_rt_sigreturn;
-
- local: *;
- };
-}
-
-/* The ELF entry point can be used to set the AT_SYSINFO value. */
-ENTRY(__kernel_vsyscall);
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .9001-linux-2.6.5-rc2-bk1/arch/i386/kernel/vsyscall.lds.S .9001-linux-2.6.5-rc2-bk1.updated/arch/i386/kernel/vsyscall.lds.S
--- .9001-linux-2.6.5-rc2-bk1/arch/i386/kernel/vsyscall.lds.S 1970-01-01 10:00:00.000000000 +1000
+++ .9001-linux-2.6.5-rc2-bk1.updated/arch/i386/kernel/vsyscall.lds.S 2004-03-22 09:53:31.000000000 +1100
@@ -0,0 +1,67 @@
+/*
+ * Linker script for vsyscall DSO. The vsyscall page is an ELF shared
+ * object prelinked to its virtual address, and with only one read-only
+ * segment (that fits in one page). This script controls its layout.
+ */
+#include <asm/fixmap.h>
+
+VSYSCALL_BASE = __FIXADDR_TOP - 0x1000;
+
+SECTIONS
+{
+ . = VSYSCALL_BASE + SIZEOF_HEADERS;
+
+ .hash : { *(.hash) } :text
+ .dynsym : { *(.dynsym) }
+ .dynstr : { *(.dynstr) }
+ .gnu.version : { *(.gnu.version) }
+ .gnu.version_d : { *(.gnu.version_d) }
+ .gnu.version_r : { *(.gnu.version_r) }
+
+ /* This linker script is used both with -r and with -shared.
+ For the layouts to match, we need to skip more than enough
+ space for the dynamic symbol table et al. If this amount
+ is insufficient, ld -shared will barf. Just increase it here. */
+ . = VSYSCALL_BASE + 0x400;
+
+ .text : { *(.text) } :text =0x90909090
+
+ .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
+ .eh_frame : { KEEP (*(.eh_frame)) } :text
+ .dynamic : { *(.dynamic) } :text :dynamic
+ .useless : {
+ *(.got.plt) *(.got)
+ *(.data .data.* .gnu.linkonce.d.*)
+ *(.dynbss)
+ *(.bss .bss.* .gnu.linkonce.b.*)
+ } :text
+}
+
+/*
+ * We must supply the ELF program headers explicitly to get just one
+ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
+ */
+PHDRS
+{
+ text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
+ dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
+ eh_frame_hdr 0x6474e550; /* PT_GNU_EH_FRAME, but ld doesn't match the name */
+}
+
+/*
+ * This controls what symbols we export from the DSO.
+ */
+VERSION
+{
+ LINUX_2.5 {
+ global:
+ __kernel_vsyscall;
+ __kernel_sigreturn;
+ __kernel_rt_sigreturn;
+
+ local: *;
+ };
+}
+
+/* The ELF entry point can be used to set the AT_SYSINFO value. */
+ENTRY(__kernel_vsyscall);
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .9001-linux-2.6.5-rc2-bk1/include/asm-i386/fixmap.h .9001-linux-2.6.5-rc2-bk1.updated/include/asm-i386/fixmap.h
--- .9001-linux-2.6.5-rc2-bk1/include/asm-i386/fixmap.h 2004-03-12 07:57:19.000000000 +1100
+++ .9001-linux-2.6.5-rc2-bk1.updated/include/asm-i386/fixmap.h 2004-03-22 09:53:31.000000000 +1100
@@ -14,6 +14,15 @@
#define _ASM_FIXMAP_H
#include <linux/config.h>
+
+/* used by vmalloc.c, vsyscall.lds.S.
+ *
+ * Leave one empty page between vmalloc'ed areas and
+ * the start of the fixmap.
+ */
+#define __FIXADDR_TOP 0xfffff000
+
+#ifndef __ASSEMBLY__
#include <linux/kernel.h>
#include <asm/acpi.h>
#include <asm/apicdef.h>
@@ -97,13 +110,8 @@ extern void __set_fixmap (enum fixed_add
#define clear_fixmap(idx) \
__set_fixmap(idx, 0, __pgprot(0))
-/*
- * used by vmalloc.c.
- *
- * Leave one empty page between vmalloc'ed areas and
- * the start of the fixmap.
- */
-#define FIXADDR_TOP (0xfffff000UL)
+#define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP)
+
#define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
@@ -148,4 +156,5 @@ static inline unsigned long virt_to_fix(
return __virt_to_fix(vaddr);
}
+#endif /* !__ASSEMBLY__ */
#endif
--
Anyone who quotes me in their signature is an idiot -- Rusty Russell
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] Centralize i386 Constants
2004-08-16 1:30 [PATCH] Centralize i386 Constants Rusty Russell
@ 2004-08-16 17:25 ` Roland Dreier
0 siblings, 0 replies; 2+ messages in thread
From: Roland Dreier @ 2004-08-16 17:25 UTC (permalink / raw)
To: Rusty Russell; +Cc: Andrew Morton, lkml - Kernel Mailing List
Rusty> __FIXADDR_TOP and PAGE_OFFSET are hardcoded in various
Rusty> places. I had to change it to run the kernel under
Rusty> qemu-fast, so I wanted to centralize them.
I like this patch -- I recently built a kernel with PAGE_OFFSET
0xb0000000 to avoid highmem on my box with 1G of RAM, based on recent
discussion, and I made the same change to vmlinux.lds.S (although
since <asm-i386/thread_info.h> includes <asm-i386/page.h>, I didn't
bother adding the "#include <asm/page.h>" line).
In any case it seems there is at least one more place where 0xc0000000
is hardcoded in arch/i386. The patch below uses PAGE_OFFSET instead
of 0xc0000000 in doublefault.c's ptr_ok() macro.
- Roland
Signed-off-by: Roland Dreier <roland@topspin.com>
--- linux-2.6.8.1.orig/arch/i386/kernel/doublefault.c 2004-08-14 03:54:50.000000000 -0700
+++ linux-2.6.8.1/arch/i386/kernel/doublefault.c 2004-08-14 10:44:55.000000000 -0700
@@ -13,7 +13,7 @@
static unsigned long doublefault_stack[DOUBLEFAULT_STACKSIZE];
#define STACK_START (unsigned long)(doublefault_stack+DOUBLEFAULT_STACKSIZE)
-#define ptr_ok(x) ((x) > 0xc0000000 && (x) < 0xc1000000)
+#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + 0x1000000)
static void doublefault_fn(void)
{
^ permalink raw reply [flat|nested] 2+ messages in thread
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2004-08-16 17:25 ` Roland Dreier
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